.checkbox-tree li {
    list-style-type:none;
    margin:0;
    padding: 10px 0px;
    position:relative
}
.checkbox-tree li::before, .tree li::after {
    content:'';
    left: 5px;
    position:absolute;
}
.checkbox-tree li::before {
    border-left:1px solid #999;
    bottom: -5px;
    top: 28px;
    overflow: hidden;
}
.checkbox-tree li:first-child::before {
    top: 28px;
}
.checkbox-tree li:last-child::before {
    bottom: 28px;
}
.checkbox-tree li a.collapse-list {
    margin-right: 10px;
}